Large-scale applications of metal nanoparticles (MNPs) in waste treatment and environmental remediation are challenging due to declining activity and stability of nanoparticles that arises from rapid aggregation during synthesis and deactivation under environmental conditions. A potential approach to overcome these problems is to confine the highly reactive MNPs in porous frameworks. In confined nano-architectures, dispersed MNPs are more stable and accessible to pollutants while integration of the support can further improve catalytic degradation of pollutants with high metal utilization. In this perspective, emerging environmental applications of confined-MNP nanocomposites are discussed, focusing on the removal of toxic heavy metals, degradation of organic pollutants and catalytic denitrification. The confinement effects are emphasised, including spatial restriction in material synthesis, enrichment and selective adsorption of reactants, and electronic interactions between metal and support. Understanding the confinement effects to guide the design of confined materials for targeted pollutants, and especially for single-atom catalysts and heteroatom doping, is highlighted.

中文翻译：

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金属纳米粒子在受限纳米空间中的污染物转化

由于在环境条件下合成和失活过程中的快速聚集导致纳米颗粒的活性和稳定性下降，因此金属纳米颗粒 (MNP) 在废物处理和环境修复中的大规模应用具有挑战性。克服这些问题的一种潜在方法是将高反应性 MNP 限制在多孔框架中。在受限的纳米结构中，分散的 MNPs 更稳定，更容易接触污染物，而载体的整合可以进一步改善金属利用率高的污染物的催化降解。从这个角度，讨论了受限 MNP 纳米复合材料的新兴环境应用，重点是去除有毒重金属、降解有机污染物和催化反硝化。强调限制效应，包括材料合成的空间限制、反应物的富集和选择性吸附以及金属和载体之间的电子相互作用。强调了解限制效应以指导目标污染物的限制材料设计，尤其是单原子催化剂和杂原子掺杂。